Your addicted brain

in #science6 years ago

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Your addicted brain


Have you ever wondered „Why do I keep taking cocaine after my last heart-attack when I almost died?“. No? Well, you are lucky then. But there are many people out there who are addicted to cocaine and many other substances dispite the negative effects on their bodies. What is the root of addiction?

How do we see?


I try to explain this rather unusual by explaining how do we see stars at night and we can’t see them when too much city light is present.
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Let’s start by explaining how do we see them in the first place. The photon from the star travels through the space a little while, like... milion years. Then it enters our atmosphere, throught the chemtrails, enters your eye where it hits the retina. Your retina is composed of two types of light sensitive cells – rod cells and cone cells. Well, now I googled there are also some „photosensitive retinal ganglion cells“. Never heard of them, fuck them. And fuck cone cells also. The story is about rod cells. On their membrane they have this awesome receptor called Rhodopsin. Inside the rhodopsin there is a molecule called retinal – derivate of vitamine A. This is the reason why you should eat carrots. The photon is basically energy and this energy can be absorbed by retinal. By absorbing the photon, retinal changes its shape. And by changing its shape, the whole receptor changes shape. And this change is the beginning of the „There is a photon!“ signal from the cell to your brain where the image is created and you can see the stars. Easy.
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Now, if you think about that, the amount of light from the stars is really low. It is far less than the light during the day. If your cells were that sensitive during the day, your brain would be overwhelmed by the signalling and you wouldn’t be able to function. So, your cells have many mechanism how to adjust the sensitivity and adapt. One mechanism is, that some rhodopsins are simply turned off and send no signal when there is more light present. And that is partially what is happening when looking at the sky by city light. Your rod cells adapt to higher level of light stimuli (city light) and as a rusult they ignore the smaller stimuli from the night sky.
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Adaptation by lowering the sensitivity. Some cells (their receptors) are turned off.

Back to the topic


OK, Peter... But why the fuck are you talking about stupid stars? Well, more precisely, I’m talking about cell adaptation. Because that‘s what is happening in addictions. Let’s take a look on alcohol. Why do you feel good when drinking? Well [oversimplification] because alcohol is causing dopamine release and dopamine is associated with the pleasant feeling. This feeling is also associated with the reward system in your brain. In other words, your brain is hard-wired to seek the stimuli causing this feeling [/oversimplification]. It is the very same brain-circuit that rewards you for eating, sexing, masturbating and buying bitcoins.

Now, alcohol (or metamphetamine, whatever) is causing exceptionally high amount of dopamine release, so your neurons are firing at exceptionally high rate and you are feeling reeeally good. But as with the cells in your retina – they tend to adapt to stimuli. Because they simply don't want to overwhelm you with signals. Your dopamin neurons are much slower than rod cells but they do eventually adapt, when stimulating longer periods of time. How do they do that? Either by lowering the synthesis of dopamin, lowering the synthesis of dopamin receptors or combination.

What does it mean? During your day, you are under constant stimuli and your brain cells react to them adequatly. You are with your partner or friends and you feel good. You are doing something meaningful and you feel good. All of that are stimuli and responses. But the brain of an addict is adapted to higher stimuli (alcohol, meth, cocaine). Simply sitting with his friends or doing something meaningful is not enough. That means that basic stimuli that would normally cause a pleasant feeling are ignored – just as the stars in the night sky. The brain of an addict is dysregulated and cannot function properly without the stimuli from the drug.
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And that is how the basics of addictions work. Well, in some cases...
I'm Peter and this is BeWise!

References:
https://www.ncbi.nlm.nih.gov/pubmed/27277868
https://www.nature.com/articles/nrn.2017.130